Looking for an effective pest control company against ants.

We had keystone, which was always great, then they were bought by Donovan which was night by Purcor and now we're getting ants inside every couple months.

They'll come back out to treat again but it doesn't seem to do anything, as the problem Lewis popping back up, which sucks because I have a pretty bad ant phobia.

I keep the place very clean, the area they keep showing up is never used for eating, and there's never been a trail, just scattered ants. I have diatomaceous earth all along the baseboard in the general area I think they're coming from, but I can't even figure out where they are getting in.

Does anyone have a service that is effective enough to not have to keep finding ants inside?